/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.management;

import com.sun.jmx.mbeanserver.GetPropertyAction;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;

import java.security.AccessController;

/**
 * This class represents numbers that are arguments to relational constraints.
 * A NumericValueExp may be used anywhere a ValueExp is required.
 *
 * <p>The <b>serialVersionUID</b> of this class is <code>-4679739485102359104L</code>.
 *
 * @serial include
 *
 * @since 1.5
 */
@SuppressWarnings("serial")
// serialVersionUID not constant
class NumericValueExp extends QueryEval implements ValueExp {

    // Serialization compatibility stuff:
    // Two serial forms are supported in this class. The selected form depends
    // on system property "jmx.serial.form":
    //  - "1.0" for JMX 1.0
    //  - any other value for JMX 1.1 and higher
    //
    // Serial version for old serial form
    private static final long oldSerialVersionUID = -6227876276058904000L;
    //
    // Serial version for new serial form
    private static final long newSerialVersionUID = -4679739485102359104L;
    //
    // Serializable fields in old serial form
    private static final ObjectStreamField[] oldSerialPersistentFields = { new ObjectStreamField("longVal", Long.TYPE), new ObjectStreamField("doubleVal", Double.TYPE), new ObjectStreamField("valIsLong", Boolean.TYPE) };
    //
    // Serializable fields in new serial form
    private static final ObjectStreamField[] newSerialPersistentFields = { new ObjectStreamField("val", Number.class) };
    //
    // Actual serial version and serial form
    private static final long serialVersionUID;

    /**
     * @serialField val Number The numeric value
     *
     * <p>The <b>serialVersionUID</b> of this class is <code>-4679739485102359104L</code>.
     */
    private static final ObjectStreamField[] serialPersistentFields;
    private Number val = 0.0;

    private static boolean compat = false;

    static {
        try {
            GetPropertyAction act = new GetPropertyAction("jmx.serial.form");
            String form = AccessController.doPrivileged(act);
            compat = (form != null && form.equals("1.0"));
        } catch (Exception e) {
            // OK: exception means no compat with 1.0, too bad
        }
        if (compat) {
            serialPersistentFields = oldSerialPersistentFields;
            serialVersionUID = oldSerialVersionUID;
        } else {
            serialPersistentFields = newSerialPersistentFields;
            serialVersionUID = newSerialVersionUID;
        }
    }

    //
    // END Serialization compatibility stuff

    /**
     * Basic constructor.
     */
    public NumericValueExp() {
    }

    /** Creates a new NumericValue representing the numeric literal @{code val}.*/
    NumericValueExp(Number val) {
        this.val = val;
    }

    /**
     * Returns a double numeric value
     */
    public double doubleValue() {
        if (val instanceof Long || val instanceof Integer) {
            return (double) (val.longValue());
        }
        return val.doubleValue();
    }

    /**
     * Returns a long numeric value
     */
    public long longValue() {
        if (val instanceof Long || val instanceof Integer) {
            return val.longValue();
        }
        return (long) (val.doubleValue());
    }

    /**
     * Returns true is if the numeric value is a long, false otherwise.
     */
    public boolean isLong() {
        return (val instanceof Long || val instanceof Integer);
    }

    /**
     * Returns the string representing the object
     */
    public String toString() {
        if (val == null)
            return "null";
        if (val instanceof Long || val instanceof Integer) {
            return Long.toString(val.longValue());
        }
        double d = val.doubleValue();
        if (Double.isInfinite(d))
            return (d > 0) ? "(1.0 / 0.0)" : "(-1.0 / 0.0)";
        if (Double.isNaN(d))
            return "(0.0 / 0.0)";
        return Double.toString(d);
    }

    /**
     * Applies the ValueExp on a MBean.
     *
     * @param name The name of the MBean on which the ValueExp will be applied.
     *
     * @return  The <CODE>ValueExp</CODE>.
     *
     * @exception BadStringOperationException
     * @exception BadBinaryOpValueExpException
     * @exception BadAttributeValueExpException
     * @exception InvalidApplicationException
     */
    public ValueExp apply(ObjectName name) throws BadStringOperationException, BadBinaryOpValueExpException, BadAttributeValueExpException, InvalidApplicationException {
        return this;
    }

    /**
     * Deserializes a {@link NumericValueExp} from an {@link ObjectInputStream}.
     */
    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        if (compat) {
            // Read an object serialized in the old serial form
            //
            double doubleVal;
            long longVal;
            boolean isLong;
            ObjectInputStream.GetField fields = in.readFields();
            doubleVal = fields.get("doubleVal", (double) 0);
            if (fields.defaulted("doubleVal")) {
                throw new NullPointerException("doubleVal");
            }
            longVal = fields.get("longVal", (long) 0);
            if (fields.defaulted("longVal")) {
                throw new NullPointerException("longVal");
            }
            isLong = fields.get("valIsLong", false);
            if (fields.defaulted("valIsLong")) {
                throw new NullPointerException("valIsLong");
            }
            if (isLong) {
                this.val = longVal;
            } else {
                this.val = doubleVal;
            }
        } else {
            // Read an object serialized in the new serial form
            //
            in.defaultReadObject();
        }
    }

    /**
     * Serializes a {@link NumericValueExp} to an {@link ObjectOutputStream}.
     */
    private void writeObject(ObjectOutputStream out) throws IOException {
        if (compat) {
            // Serializes this instance in the old serial form
            //
            ObjectOutputStream.PutField fields = out.putFields();
            fields.put("doubleVal", doubleValue());
            fields.put("longVal", longValue());
            fields.put("valIsLong", isLong());
            out.writeFields();
        } else {
            // Serializes this instance in the new serial form
            //
            out.defaultWriteObject();
        }
    }

    @Deprecated
    public void setMBeanServer(MBeanServer s) {
        super.setMBeanServer(s);
    }

}
